Seroprevalence of Toxoplasma gondii Infection among HIV/AIDS Patients in Eastern China

Guoqiang Shen,Xiaoming Wang,Hui Sun,Yaying Gao 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.1

Toxoplasmosis, a neglected tropical disease caused by the protozoan parasite Toxoplasma gondii, occurs throughout the world. Human T. gondii infection is asymptomatic in 80% of the population; however, the infection is life-threatening and causes substantial neurologic damage in immunocompromised patients such as HIV-infected persons. The major purpose of this study was to investigate the seroprevalence of T. gondii infection in subjects infected with HIV/AIDS in eastern China. Our findings showed 9.7% prevalence of anti-T. gondii IgG antibody in HIV/AIDS patients, which was higher than in intravenous drug users (2.2%) and healthy controls (4.7%), while no significant difference was observed in the seroprevalence of anti-Toxoplasma IgM antibody among all participants (P>0.05). Among all HIV/AIDS patients, 15 men (7.7%) and 10 women (15.9%) were positive for anti-T. gondii IgG antibody; however, no significant difference was detected in the seroprevalence of anti-Toxoplasma IgG antibody between males and females. The frequency of anti-Toxoplasma IgG antibody was 8.0%, 13.2%, 5.5%, and 0% in patients with normal immune function (CD4<SUP>+</SUP> T-lymphocyte count ≥500 cells/ml), immunocompromised patients (cell count ≥200 and <500 cells/ml), severely immunocompromised patients (cell count ≥50 and <200 cells/ml), and advanced AIDS patients, respectively (cell count <50 cells/ml), while only 3 immunocompromised patients were positive for anti-T. gondii IgM antibody. The results indicate a high seroprevalence of T. gondii infection in HIV/AIDS patients in eastern China, and a preventive therapy for toxoplasmosis may be given to HIV/AIDS patients based on CD4<SUP>+</SUP> T lymphocyte count.

Studies on The Propagation Characteristics of Apple Plantlets Repeatedly Subcultured in Vitro

Xiaoxin Shi,Guoqiang Du,Yi Gao,Baokun Ma 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Cavity and Interface effect of PI-Film on Charge Accumulation and PD Activity under Bipolar Pulse Voltage

Akram, Shakeel,Wu, Guangning,Gao, GuoQiang,Liu, Yang The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.5

With the continuous development in insulation of electrical equipment design, the reliability of the system has been enhanced. However, in the manufacturing process and during operation under continues stresses introduce local defects, such as voids between interfaces that can responsible to occurrence of partial discharge (PD), electric field distortion and accumulation of charges. These defects may lead to localize corrosion and material degradation of insulation system, and a serious threat to the equipment. A model of three layers of PI film with air gap is presented to understand the influence of interface and voids on exploitation conditions such as strong electrical field, PD activity and charge movement. The analytical analysis, and experimental results are good agreement and show that the lose contact between interfaces accumulate more residual charges and in consequences increase the electric field intensity and accelerates internal discharges. These residual charges are trapped charges, injected by the electrodes has often same polarity, so the electric field in cavities increases significantly and thus partial discharge inception voltage (PDIV) decreases. Contrary, number of PD discharge quantity increases due to interface. Interfacial polarization effect has opposite impact on electric field and PDIV as compare to void.

Cavity and Interface effect of PI-Film on Charge Accumulation and PD Activity under Bipolar Pulse Voltage

Shakeel Akram,Guangning Wu,GuoQiang Gao,Yang Liu 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.5

With the continuous development in insulation of electrical equipment design, the reliability of the system has been enhanced. However, in the manufacturing process and during operation under continues stresses introduce local defects, such as voids between interfaces that can responsible to occurrence of partial discharge (PD), electric field distortion and accumulation of charges. These defects may lead to localize corrosion and material degradation of insulation system, and a serious threat to the equipment. A model of three layers of PI film with air gap is presented to understand the influence of interface and voids on exploitation conditions such as strong electrical field, PD activity and charge movement. The analytical analysis, and experimental results are good agreement and show that the lose contact between interfaces accumulate more residual charges and in consequences increase the electric field intensity and accelerates internal discharges. These residual charges are trapped charges, injected by the electrodes has often same polarity, so the electric field in cavities increases significantly and thus partial discharge inception voltage (PDIV) decreases. Contrary, number of PD discharge quantity increases due to interface. Interfacial polarization effect has opposite impact on electric field and PDIV as compare to void.

Factors Influencing Bond Properties in Concrete Encased Steel Columns at High Temperatures

Yuzhuo Wang,Ziqing Liu,Guoqiang Li,Jian Jiang,Ying Gao,Chuanguo Fu 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.3

This paper presents experimental results on factors governing the bond strength between steel and concrete in concrete encased steel (CES) columns at high temperatures. Push-out tests were conducted on 22 CES specimens to investigate the bond strength between concrete and steel under the temperature of 250 °C, while one specimen was tested at room temperatures for comparison. Data obtained from these tests revealed that the bond properties of CES structures between steel and concrete is infl uenced by a number of factors, including concrete strength, concrete cover thickness, stirrup reinforcement ratio, steel ratio and anchorage length of steel at high temperatures. The formulas for predicting the ultimate bond strength and slip between steel and concrete of CES structures are proposed based on the experimental investigations.

Degradation reliability modeling of plain concrete for pavement under flexural fatigue loading

Jia, Yanshun,Liu, Guoqiang,Yang, Yunmeng,Gao, Ying,Yang, Tao,Tang, Fanlong Techno-Press 2020 Advances in concrete construction Vol.9 No.5

This study aims to establish a new methodological framework for the evaluation of the evolution of the reliability of plain concrete for pavement vs number of cycles under flexural fatigue loading. According to the framework, a new method calculating the reliability was proposed through probability simulation in order to describe a random accumulation of fatigue damage, which combines reliability theory, one-to-one probability density functions transformation technique, cumulative fatigue damage theory and Weibull distribution theory. Then the statistical analysis of flexural fatigue performance of cement concrete tested was carried out utilizing Weibull distribution. Ultimately, the reliability for the tested cement concrete was obtained by the proposed method. Results indicate that the stochastic evolution behavior of concrete materials under fatigue loading can be captured by the established framework. The flexural fatigue life data of concrete at different stress levels is well described utilizing the two-parameter Weibull distribution. The evolution of reliability for concrete materials tested in this study develops by three stages and may corresponds to develop stages of cracking. The proposed method may also be available for the analysis of degradation behaviors under non-fatigue conditions.

Acid-free epoxidation of soybean oil with hydrogen peroxide to epoxidized soybean oil over titanium silicalite-1 zeolite supported cadmium catalysts

Lei Cai,Chao CHEN,Wenjun Wang,Xiu Gao,Xiaoyan Kuang,Yan Jiang,Liang Li,Guoqiang Wu 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.91 No.-

Titanium silicalite-1 (TS-1) zeolite was successfully synthesized by hydrothermal method in the presenceof the tetrapropylammonium hydroxide (TPAOH) template, and a series of TS-1 supported cadmium withdifferent Cd loading (xCd/TS-1) catalysts were carefully prepared to produce epoxidized soybean oil(ESO) through the acid-free catalytic epoxidation of soybean oil (SO) with H2O2. These catalysts were fullycharacterized using various modern techniques and further evaluated systematically in this epoxidationreaction to understand the relationship between catalytic activity and structure of active components. The results show that the highly dispersed Cd species are introduced on the TS-1 support withoutaffecting the coordination environment of tetrahedral Ti (framework Ti). Furthermore, the Cd species arecoordinated with tetrahedral Ti species via O atom resulting in the weakness of the Ti–O bonds and facileattack of the Ti–O bonds by alcohol and H2O2, which can easily form thefive-membered intermediate andpromote the SO epoxidation process. Furthermore, the deactivation and regeneration behaviors of 2%Cd/TS-1 catalyst in SO epoxidation were also investigated, which reveal that the catalyst deactivation of cokedeposition is due to the strong adsorption of the catalysts and SO molecules. But the spent 2%Cd/TS-1 canbe completely regenerated by calcination method.

PREDICTING SAFER VEHICLE FONT-END SHAPES FOR PEDESTRIAN LOWER LIMB PROTECTION VIA A NUMERICAL OPTIMIZATION FRAMEWORK

Guibing Li,Huaxing Ma,Tongqi Guan,Guoqiang Gao 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.3

Lower limb injuries occur frequently in vehicle-to-pedestrian collisions and vehicle front-end shape has a significant influence on pedestrian lower limb injuries Therefore, the aim of the current study is to propose an effective optimization framework for vehicle front-end design and to predict safer vehicle front-end shapes for pedestrian lower limb protection using this optimization framework. To achieve this, an optimization framework combining the genetic algorithm (GA) in MATLAB and finite element (FE) simulations in LS-DYNA was proposed and applied to predict safer vehicle frontend shapes for pedestrian lower limb protection. The optimization results indicate that it is feasible and reliable to use the proposed optimization framework in vehicle front-end shape optimization for pedestrian lower limb protection. The predicted safer vehicle front-end shapes suggest that the vehicle front-end designs with a lower bumper stiffener close to the ankle, a bumper absorber higher than the knee and a bonnet leading edge above the hip joint would be beneficial for pedestrian lower limb protection. Biomechanical analysis implies that a plane-approximating support to both the upper and lower leg from the vehicle front-end structure could reduce lower limb lateral bending and hence injury risk greatly.

The characteristic analysis of the operational overvoltage caused by the vacuum circuit breakers on High-speed trains

Xiao Song,Tong Mengyuan,Rao Yang,Li Yuhang,Ye Zhizong,Shen Yixiang,Hou Hao,Gao Guoqiang,Wu Guangning,Jin Yaoyao,Zhou Jie,Liu Jie 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.1

Along with the operating velocity and traction power increasing continuously, the issue related to the safety and reliability of the high-voltage traction power system for high-speed trains have gradually been exposed during the practical service process. When the train passes a neutral section settled roughly per 15 km between two neighboring substations, the on-board vacuum circuit breaker (VCB) must to be operated for changing the input powers with diff erent phases. At the moment of switching on or off the VCB, the arc between the contacts in the arc-extinguishing chamber may be triggered, which tends to result in the operational overvoltage. Due to numerous inductances and capacitances existing in the traction power supply system, the overvoltage may lead to high-frequency electromagnetic oscillation spreading along the transmission routes. The on-board high-voltage equipments within the power supply system may suff er from the impulse brought from the VCB operational overvoltage frequently, which is possible to cause the insulation aging or breakdown issue. To investigate the characteristic of the operational overvoltage of VCBs, a ‘train-rail-catenary’ power supply model is built based on the measured impedance parameters, which has been verifi ed by the experimental tests. The generating mechanism with the infl uence factors of the operational overvoltage when switching on or off the VCB has been explored, meanwhile the distribution of the train body overvoltage on each carriage has also been presented.